An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The Keplerian orbit that a satellite would follow after a specific time t if all forces other than central inverse-square forces ceased to act from time t on. An osculating orbit is tangent to the real, perturbed, orbit and has the same velocity at the point of tangency.

→ osculating; → orbit.

For a curve C at a point p, the limiting plane obtained from taking planes through the tangent to C at p and containing some variable point p' and then letting p' approach p along C.

→ osculating; → plane.

For a curve C at a point p, the limiting sphere obtained by taking the sphere that passes through p and three other points on C and then letting these three points approach p independently along C.

→ osculating; → sphere.

The contact between two osculating curves or the like.

Verbal noun of → osculate

A → spacecraft whose goal is to collect a sample from the asteroid → 101955 Bennu and bring it back to Earth. It was launched by → NASA on September 8, 2016. OSIRIS-REx will spend two years chasing Bennu down, finally rendezvousing with the → near-Earth asteroid in August 2018. The spacecraft will then study the → asteroid Bennu from orbit for another two years before grabbing at least 60 grams of surface material in July 2020. The sample should reach Earth in 2023. The analysis of the sample would allow to study the role that → B-type asteroids like Bennu, which are primitive and apparently carbon-rich, may have played in helping life appear on Earth.

The name is short for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer .

A very hard, brittle metal belonging to the → platinum group elements; symbol Os. → Atomic number 76, → atomic weight 190.2, → melting point 3,045 °C, → boiling point 5,027 °C, → specific gravity 22.57 at 20°C. It was discovered in 1803 simultaneously with → iridium in a crude → platinum ore by the English chemist Smithson Tennant.

From Gk. osme "smell" because of the sharp odor of the volatile oxide.

The process by which solvent molecules pass through a partially permeable membrane from a dilute solution into a more concentrated solution, thus equalizing the concentrations of materials on either side of the membrane. → permeability.

Extracted from Fr. endosmose "endosmosis" and exosmose "exosmosis," from Gk. prefixed osmos "a thrusting, a pushing," from othein "to push, to thrust;" cf. Av. vādāiiôit "breaks through, hunts," vadah- "wedge;" Mod.Pers. guvah, gavah "wedge;" Skt. vadh- "to slay, kill," vadha- "killer."

Tarârân, literally "pushing across," from tarâ-, → trans-, + rân present stem of rândan "to push, drive, cause to go," causative of raftan "to go, walk, proceed" (present tense stem row-, Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack").

The hydrostatic pressure produced on the surface of a partially permeable membrane by osmosis.

→ osmotic; → pressure.

An approximate empirical criterion for the stability of a → galactic disk against its collapse to form a bar. The disk is stable if the following relation holds: T/|W| < 0.14, where T is the rotational → kinetic energy and |W| is the absolute value of the gravitational → potential energy. While the → Toomre criterion applies only to small linear perturbations, the Ostriker-Peebles criterion describes global modes.

Ostriker & Peebles, 1973, ApJ 186, 467; → criterion.

1a) Being the one (as of two or more) remaining or not included.
1b) Being the one or ones distinct from that or those first mentioned or implied.
1c) Not the same; different.
1d) Additional.
2) To treat or consider (a person or a group of people) as alien to oneself or one's group (as because of different racial, sexual, or cultural characteristics)

M.E., from O.E. ôther; related to O.Saxon athar, O.Norse annarr, Du. ander, O.H.G. andar, Ger. ander, ultimately from PIE *an-tero- (cf. Lith. antras, O.Prussian anters.

Digar "another, other," from Mid.Pers. dit, ditikar "the other, the second," O.Pers. duvitiya- "second," Av. daibitya-, bitya- "second," Skt. dvitiya- "second," PIE *duitiio- "second."

An action by which an individual or group becomes classified in somebody's mind as "not one of us". See also: → in-group, → out-group.

→ other; → -ing.

Characteristic of the Other.

→ other; → -ness.

Away from, or not in, the normal or usual place, position, state, etc.

O.E. ut; (cf. O.N., O.Fris., Goth. ut, Du. uit, Ger. aus; PIE base *ud- "up, up away" (cf. Pers. os-, as below; Gk. hysteros "the latter;" L. usque "all the way to, without interruption;" O.Ir. ud- "out;" Rus. vy- "out").

Borun, variant birun "out, the outside," from Mid.Pers. bêron, from bê "outside, out, away," variant bêg, as in bêgânag (cf. Sogh. bêk "out, outside, apart, except," bêk-dênê "heretic," literally "out of religion") + rôn "side, direction;" Av. ravan- "(course of a) river").
Os-, from Mid.Pers. us-, uz-; Av. uz-, us- "out of, outside, from;" O.Pers. ud- (ud-apatatā "to rise up, rebel"), also Pers. preposition az "from; of; out of," prefixes zo- (in zodudan "to polish, clean;" Mid.Pers. uzdâtan; Av. uzdā-, from uz- + dā- "to make, create"), âz- (âzmâyeš, → experiment), haz- (haziné "cost, expenditure;" Mid.Pers. uzên, uzênak, from *uz-ayana- "going out;" Av. us- + ay- "to go" (→ assembly); PIE *ud- "up, out," cf. Skt. úd "up, away, out;" E. out, as above.

The condition of two oscillators that have the same frequency but different phases. Opposed to → in phase.

→ out; → phase.

A group to which the speaker, the person spoken of, etc. does not belong.

→ out; → group.

Nâxodi, opposite of xodi "in-group," from nâ- "not," → un-, + xodi, → in-group.

1) A fairly brief period of unusually strong gas and/or dust production from a comet nucleus.
2) A brief period of enhancement of emission from a star, a quasar, etc.

→ out; → burst.

A phase in the → light curve evolution of eruptive objects such as → dwarf novae, → Soft X-ray Transients, and transient → magnetars which follows the characterized sudden increase in their flux (over a factor ~ 1000 over the quiescent level). Outburst decay is slow and lasts months or years.

→ outburst; → decay.

A final product or end result; consequence; issue (Dictionary.com).

→ out; → come.

Borunšod "outcome," from borun, → out, + šod, šodan "to go, to pass, to change," → become.

Emergence of a particular rock-body, e.g. a stratium or vein, at the ground surface. Outcrops can be formed naturally or by human action. Stream erosion and highway construction can produce outcrops.

Noun use of crop out, from crop, from M.E., O.E. cropp "bird's craw," also "head or top of a sprout or herb;" → out.

Borunzad, literally "strike out," from borun, birun, → out, + zad, zadan "to strike, beat," from Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *g^when- "to strike, kill."

Being or located on or toward the outside; external.

→ out + -er suffix of comparative degree of adjectives.

→ external.